Among 243 patients who received kidney transplants at our center, two patients suddenly developed a severe debilitating pain syndrome in the lower limbs.
Case no. 1A 49-year-old male patient who received a deceased donor kidney transplant, in therapy with tacrolimus (plus steroids and perioperative basiliximab). One month after transplantation he reported joint pain in his ankles, knees, feet, and hands. The pain became so intense that the patient was forced to use crutches to walk. Clinical examination revealed intense pain at movement, without edema, redness, increase in temperature, or cutaneous trophic alterations. The patient was receiving tacrolimus 5 mg b.i.d. with levels between 5 and 10 ng/ml. There was no clinical or serologic evidence of rheumatic disease or rhabdomyolysis. The rise in serum creatinine was attributed to heavy non-steroidal antiinflamatory drug use. After withdrawing these agents, the serum creatinine decreased to 1.6 mg/dl. Bone radiographies showed osteoporosis at the heads of the knee, ankle, tarsal, and metatarsal bones. An ultrasound scan of the joints highlighted a minimal amount of articular effusion and a mild synovial reaction in the knee and foot joints. Magnetic resonance imaging (MRI) of the left knee showed an area of bone marrow edema in the external condyle of the femur and wearing of the cartilage (Figure 1). Computerized bone mineralometry showed a slight reduction of the bone mass, whereas bone scintigraphy revealed increased radionuclide uptake in the affected joints (Figure 2).